Many processes are used in the creation of a semiconductor device. For example, one or more of these processes may be an ion implant process, where ions are energetically injected into the workpiece. In certain embodiments, ions are only implanted into certain portions of a workpiece. This process may be referred to as a selective implant or a patterned implant.
In certain embodiments, patterned implants are performed by applying a photoresist to the portions of the workpiece that are not to be implanted. In these embodiments, ions are accelerated toward the workpiece. However, ions that strike the photoresist are blocked from impacting the underlying workpiece.
High temperature implants are becoming more common, as certain semiconductor parameters may be improved through the use of high temperature implants. For example, high temperature implantation of arsenic for finFET extension regions has been demonstrated to improve finFET performance, as compared to room temperature implants.
The use of photoresist for patterned implants is very common, however, it also has drawbacks. One such drawback is the temperature limits of the photoresist. Specifically, at high temperatures, such as above 150° C., the photoresist is ineffective at blocking ions and also may not retain its structure. Therefore, traditional photoresist is not useful for these high temperature ion implants.
Therefore, it would be beneficial if there were a method of selectively implanting a portion of a workpiece at high temperatures. Further, it would be advantageous if this selective implanting did not introduce a significant number of addition processes to the overall semiconductor manufacturing process.